Date: Mon, 06 Jan 1997 20:32:27 +1100 (EST) From: peter.jeremy@alcatel.com.au To: FreeBSD-gnats-submit@freebsd.org Subject: i386/2381: gcc built with i486 default can't compile biosboot files Message-ID: <199701060932.UAA27078@vk2pj.alcatel.com.au> Resent-Message-ID: <199701060940.BAA23243@freefall.freebsd.org>
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>Number: 2381
>Category: i386
>Synopsis: gcc built with i486 default can't compile biosboot files
>Confidential: no
>Severity: serious
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Mon Jan 6 01:40:01 PST 1997
>Last-Modified:
>Originator: Peter Jeremy
>Organization:
Peter Jeremy (VK2PJ) peter.jeremy@alcatel.com.au
Alcatel Australia Limited
41 Mandible St Phone: +61 2 9690 5019
ALEXANDRIA NSW 2015 Fax: +61 2 9690 5247
>Release: FreeBSD 2.1-STABLE i386
>Environment:
gcc built with i486 as default target CPU.
>Description:
When gcc is built with the i486 as the default target, code alignment is
increased to match the i486 cache. This has the side-effect of increasing
code size. In most cases, this is unimportant, however the BIOS bootstrap
programs are restricted in size and the increased code size causes the
stage 2 bootstrap to exceed its allowable size.
>How-To-Repeat:
# cd /sys/i386/boot/biosboot
# make (or make "CC=cc -m486")
...
cp -p boot boot.strip
strip boot.strip
size boot.strip
text data bss dec hex
8048 112 51132 59292 e79c
dd if=boot.strip of=boot.nohdr ibs=32 skip=1 obs=1024b
255+0 records in
0+1 records out
8160 bytes transferred in 1 secs (8160 bytes/sec)
ls -l boot.nohdr
-rw-rw-r-- 1 root wheel 8160 Jan 4 13:10 boot.nohdr
dd if=boot.nohdr of=boot1 bs=512 count=1
1+0 records in
1+0 records out
512 bytes transferred in 1 secs (512 bytes/sec)
dd if=boot.nohdr of=boot2 bs=512 skip=1
14+1 records in
14+1 records out
7648 bytes transferred in 1 secs (7648 bytes/sec)
*** Boot2 is too BIG ***
*** Error code 2
Stop.
#
>Fix:
Force gcc to assume an i386 (and hence align to words rather than
cache lines) when building the BIOS bootstraps:
*** /cdrom/usr/src/sys/i386/boot/biosboot/Makefile Mon Jul 1 12:35:36 1996
--- /usr/src/sys/i386/boot/biosboot/Makefile Sun Dec 15 09:53:24 1996
***************
*** 11,16 ****
--- 11,17 ----
CFLAGS= -O2 -DDO_BAD144 -DBOOTWAIT=${BOOTWAIT} -DCOMCONSOLE=0x3F8
CFLAGS+= -DBOOTSEG=${BOOTSEG} -DBOOTSTACK=${BOOTSTACK}
CFLAGS+= -I${.CURDIR} -I${.CURDIR}/../..
+ CFLAGS+= -m386 # Reduce alignment requirements so it fits
# force usage of serial console instead of keyboard probing
#CFLAGS+= -DFORCE_COMCONSOLE
>Audit-Trail:
>Unformatted:
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